A directory is an index of entry names (i.e., “relative distinguished names”) and information associated with each entry name. Directories can be used for a variety of purposes, from providing telephone number and address information (i.e., a telephone directory) to maintaining service plan information for wireless telephone service subscribers. One particular use of an electronic directory is to correlate user information with electronic mail services for an electronic mail service center. In this arrangement, the electronic mail service directory includes an index of names for each user of the electronic mail services. The directory then associates each user name with particular information related to that user, such as the specific electronic mail services available to the user. One type of electronic directory is the X.500 directory, which employs the protocols recommended by the International Telecommunication Standardization Sector (ITU-T) for client/server systems that maintain and access directories of user and resources in X.400 form.
An electronic mail service center or hub may service a number of different users (or subscribers) with various electronic mail-capable devices under one domain. Accordingly, some of the electronic mail users may need a robust mail server that allow a user to designate “email aliases” for message delivery. To successfully employ these aliases, the electronic mail service directory will typically maintain a separate directory entry for each user. The electronic mail service directory may also require some post processing of information added to the directory, in order to completely populate a directory entry.
Due to the inherent flexibility of a directory, the content of the entries in a directory can vary greatly. An electronic mail service provider, however, may require consistency in both the structure and content of these entries. Of course, users of other types of directories may also require consistent structure and content in their directory entries. Accordingly, there is a need for a service that maintains consistent content in a directory. More particularly, there is a need for a service that rejects attempts to add information to, modify information in or delete information from a directory that violate predetermined rules for controlling the directory's content.
A variety of protocols have been developed for finding, adding, deleting and modifying information in a directory. For example, the Lightweight Directory Access Protocol (LDAP) is a protocol developed to manipulate transmission control protocol/Internet protocol (TCP/IP) stacks to extract information from (or add information to) a hierarchical directory such as a X.500 type directory. These protocols, however, do not give the directory provider (i.e., the entity that maintains the directory) the ability to control the consistency of content added to, modified in or deleted from a directory. Instead, a directory provider must typically employ some type of back-end proprietary database scheme to enforce the consistency of content in a directory. This arrangement has a number of drawbacks. For example, a user seeking to add prohibited information to a directory will not usually be informed that the information is prohibited. Instead, the information is simply refused entry into the directory, and the user is unaware that the submitted information has been rejected.